In order to achieve reliable broadcast-quality motion picture experts group (MPEG) audio/video (A/V) distribution in an MPEG A/V delivery system, the audio and video received and encoded at an MPEG server typically must be played back at an MPEG client at substantially the same rate at which the MPEG data was received at the server. This matching rate significantly contributes to the reliable delivery of A/V data as it allows the decoder at the MPEG client to consume A/V data at the rate at which it was generated, thereby reducing or avoiding buffer underflow or overflow and thus reducing or eliminating artifacts in the displayed video and audio. In view of the benefits of the matching rate requirement, the MPEG standards, e.g., ISO/IEC 13818, typically institute a quality requirement that the jitter between the server and the client remain within +/−500 nanoseconds (ns). Accordingly, the MPEG standards implement elaborate mechanisms in an effort to fulfill this jitter requirement in standard broadcast systems. These mechanisms typically are satisfactory in satellite, cable or terrestrial delivery systems due to the near constant delay between the server and the client. However, in wireless networks and other similar networks, these mechanisms often fail because the wireless links typically do not exhibit a substantially constant delay between wireless devices. To illustrate, in IEEE 802.11 applications, the frequency, and thus the symbol rate, used to transmit information is dependent on the distance between the transmitter and the receiver. Accordingly, as the distance between the server and client varies, so does the jitter in the transmission of MPEG data between the server and client. Similarly, obstructions between the server and the client may cause dynamic changes in the symbol rate, thereby resulting in dynamic changes in the transmission time and therefore the jitter of MPEG data.
The magnitude of jitter also may increase as a result of the implementation of MPEG delivery systems within a network, such as a local area network (LAN), a wide area network (WAN), a metropolitan area network (WAN), the Internet and the like. In these instances, the transmission of MPEG data from a server to a client typically would require the processing of the MPEG data at various layers of the network stack (e.g., the telecommunications protocol/internet protocol (TCP/IP) stack) at the server, the transmission of the processed MPEG data via a wireless medium, and then the subsequent processing of the MPEG data at various layers of the network stack at the client. Considerable additional jitter maybe introduced due to variances in the software and hardware implementing these network stacks. The overall jitter resulting from these variances may be of such magnitude so as to prevent the client from synchronizing to the server. Accordingly, improved techniques for synchronizing devices in wireless environments so as to reduce jitter would be advantageous.